Steam generator



Nov. 3, 192 1,559,7 3

' H. A. NICHOLSON STEAM GENERATOR rum May 10., 1919 4 Shuts-Shoot 1 wa QATTORNEY {ma KAZW' Nov."3,19z5.- 1,559,763

H. A. NICHOLSON STEAM GENERATOR Filed May 10. 1919 4' Shuts-Shut 2INVENTOR ATTORNEY Nov. 3', 1925. 1,559,763

H. A? NICHOLSON I swam esuanxron I Filed May 10, 1919 4 Shoots-Shut 3 &

ATTORNEY Nov. 3 1925.

' H. A. NICHOLSON swam GENERATOR Filed law 10, 1919 4 Sheets-snout 4iNVENTOR ATTORNEY Patented Nov. 3, 192 5.

UNITED STATES 1,559,763 PATENT OFFICE.

HENRY A. mononson, or ARVKLES BAY, AUCKLAND, AssIGNonmo ERNEST acmre, onAUCKLAND, NEW mas ive.

' s'rnAM GENERATOR.

Application filed May 10,

To aZZ whom it may concern:

Be it known that I, HENRY A. NIoHonsoN, a citizen of New Zealand, and asubject of the King of Great Britain, residing in Ark- :les. Bay,Auckland, New Zealand, haveinvented certain new and useful Improvefments inj Steam Generators, of which the following is a specification. 1This invention relates to steam generators of the class set forth in mypending application 284,657, in which water advancing through a' singletubular circuit is gradually heated to a high temperature and itsconversion into steam completed as it .enters the steam drum.

According to the present construction, the flames may pass directly froma fire box of simple type into a chamber which contains a grid of watertubes, the tubes being space apart to facilitate heating, and the flamesbeing compelled to follow a zigzag course up through the flame chamberby means of box, one of the doors and door plates being removed todisclose the interior.

a system of baffle plates, which are inserted between certain rows oftubes. [Thus there higher than that which it is necessary to maintain inthe service steam "drum. 7 A reserve of heated water is provided in adrum arranged between the, grid and the force pump which supplies thewater, as

set forth in said application.

The heated fluid is delivered from the grid into a steam drum, which isprovided with a converting device, the pressure being preferably reducedabout fifty pounds, so that the heated fluid which reaches the drumunder high pressure is let into the drum in the form of steam at a lowerpressure. The

converting dev ce may regulate the pressure of steam in the servicedrum.v

Provision is also made to guard against (1' ing valve used at the inletof the stea is provided an inexpensive and simple apparatus for heatingthe fluid to a pressure.

1919. Serial No. 296,086.

an. obstruction to the delivery of highly heated fluid from the grid tothe delivery drum. This is evident because the service valye would blowoff if the pressure in the dellvery "drum were above normal, Whereas theblowing off of the special valve shows that pressure is excessivelyabove normal in the reserve water drum. Other features and advantageswill heremafter appear. I

In the accompanying drawings,

Figure 1 is a part-sectional side elevation of ,a steam generatorembodying the present improvements in oneform.

Figure 2 is an edge elevation of a preferredform of baffle plate for theflames used in the grid chamber of the generator.-

Figure 3 is a detail of a pressure-reducdrum. I 7 5 Figure 4 is a planof the generator. Flgure 5 1s a front elevation of the fire Figure 6 isa diagram to show the operation of the apparatus. I

Figure 7 s a sectional elevation takentransversely of the flame chamber,showing the arrangement of the grid and baflle plates therein.

The fire box comprises side walls 20, rearwall 21 and-top 22, allofwhich may be of brick; the top being supported by a bridge or crownlate 23. In'the front wall 24 of the fire ox are arranged verticalframes '90 or plates 25, each having a fuel door 26 and an ash 'd0or'The fuel rests upon a grate 28:."

In the upper part of the' rear Wall is formed an opening 29, for thepassing of flames into a flame chamber, which comprises-a frontwall 30,a rear wall 31, and side walls 32, 33; the flames passing in azigzag-course through this chamber, to heat the water which is advancing1n av set of tubes forming a grid, which will presently be described.The hot gases vent through a'chimney 34, having a damper 35. The air ispreferably passed through the fuel by forced draft. 3 The water fromwhich the steam is generated is supplied by a force pump '36, a reserveofwater being accumulated in a drum 37, through which the pumpcommunicates by means of a main 38 rising therefrom, 110

where it is exposed. to the outflowing hot gases and heated thereby.Said :rid chamber or flame .-hamber- 30, 31., 32. 33 1s surmounted by adome whose walls are indicated at id. 4-]. and this water drum isarranged in said dome so that the gas will eireulate on all sidesthereof, as set forth in my said eonipauion applieation 984.657. It.will be seen at Figure t that the. drum is eouneeted to the horizontalportion of the supply main 39. by a short branch or fittingr 42.

hilo the boiler is steaming. a "alve 43 in the pipe 82 is closed. sothatall the water that is forced through 39 by the pump enters the hotwater drum 3?, keeping the latter tilled with water.

An outlet 44 is plated in the top of the drum, so as to insure that thedrum shall keep filled with water. This is evident be eause it any steamshould form in the drum. it must first pass through the outlet it.permittine water to rise/in the drum. in other words. steam eannot betrapped in the drum.

The water flows out through a short horizontal pipe 45, and down througha vertieal pipe 46 to the middle of a distributor 47, at whose ends areelbows 48 joined to headersdt). so at the top of the flame ehamher.These headers extend horizontally along the sides of the ehamher. Fromthe headers the Water flows down through a grid, and is collected at thebottom by means of other horizontal side-headers 5], 52. ends of thestrips 23 and 28 are equipped The grid is eomposed of vertieal sections.I

eaeh seetion eomprising horizontal transverse tubes 52;, through whichthe water flows down in a zigzag eourse. as \vill be understood fromFigure 7: the tuhes being eonneeted at their rear ends alternately byeouplings or vert eal tubes or passages 54 provided in vertical headers55, which may he. ot the eons-traction set forth in said applieationQfiltm. 'lhese grid sections e0nneet alternately with headers 49, 50,the upper tube in eaeh grid section having a. coupling 56 opening intoheader 4.) or 50,

. and the lower tube in the same section haveither distributing header49 or 50 flows.

ing a eoupling 57 opening into lower header 51 or 52; the preferredconstruction being such that the uppermost tube eonneets with thehorizontal distributing header on one.

side. while the lowest tube eonneet-s with the horizontal roller-ting:header on the other side. It will be seen that thowater from down inazigzag course through the flame chamber and is, collected in one of thebot.- tom headers 51 or 52, at the delivery portion of the generator.(The vertical section headers are provided with scre w plugs 58"for-Cl6tlD-Ulli. openings formed therein-opposite n V100, eonsisting ot avatirezk'tt inch may ture 80 within the drum, and earryingy, 2

the ends of the tubes. Each grid section is a unit. being connected at.its upper end. at one side by flanges 59 to flanges on the up perheader, and at the bottom on the other side by flanges 6O bolted toflanges on the hot-tom header. Adjustable supports in the form of serewstil may be provided for the remaining corners of each grid section.

A system of battle plates 62, 63, 8%., 65, and 66 may be, provided fordirecting the flames in a zigzag path up through the grid filifitle her;said plates being preferably of eorru gated form for strength, asindicated in Figure 2; this form of plate having plain supportingflanges 67 at its ends.

flanges may rest upon lugs (38 provided upon some or all of the verticalheaders ot the grid seetions; the plates being slidden hori' zontallyforward into position upon these lugs before the rear Wall 31 of thegrid chamber is set up.

As seen at Figure 1, these battle plates are all too short to extendtrmn frontentireiy to the haelc ot' the grid chamber. 'ihey are setalternately against the. front and hook waits, so as to leave flame.passages at alternate ends. The hailie, plates (32, {54, and $6, forexample. are set against the front well, while plates 63 and 65 may beset against the rear wall.

At the top of the flame chamber, sur mounting the top row of tithes, mayhe pro vided a special battle piate 68, which he mueh shorter than theothers, to leave a broad opening for the vent. ot flames and hot gasesfrom the grid chamber,

'lhese battle plates are placed between a, ternate horizontal rows oftubes as illns trated. the rows of tubes being nun'ierous, and thebattle plates being preferably not so numerous as to interfere with theproper flow ot' flames and hot gases through the grid chamber.

From the collecting headers 51, 52, the heated fluid is deliveredthrough vertical pipes or mains 'i't). and horizontal pipes Z1 andinlets 72, to the ends of a stoma drum 73. At each inlet 72 is fiat-ed adevice whereby the remnant of the aid whi'eh is in water 315 form andwhich reaches said inlet, under high pressure may he eonverted and enterthe drum in the form o'i'teteani. At Figure 3 is illustrated one formoteonrerting the elosethe inlet or orifice i5 provided in the tlrununnclmayhare a horizontal gun-hug.

t i- "*4 stem 76. pivoted at 74 to the. short arm tti of an elbow ieverpivoted at T9 upon a ti adjustable weight 8i; said weight: Being:

preferably adjusted to such point that the ressure of steam within thedrum is ru -uat-efl to fifty pounds less than that. of the heated fluidin the delivery main "The steam drum isin communication with only thedelivery end of the system of water pip ing, which system includes thegrid.

*hen the generator is beingheated up, the valve 43 is opened, thuspermitting circulation of Water as it becomes warmed.- At this time, thepump is not working. The heated water rises to the top of the gridsystem, and the cooler water flows to the bottom of the apparatus, sothat a. circulation is set up by the heated water rising in the grid.The coolest water reaches the, lower headers 51 and 52, and uponbecoming heated rises in the grid, flowing through the distributer 47 tothe drum 37, whence it may flow down through the main 82 (containingsaidvalve 43), down throughpipes 71, 70 to the bottom of the system.This circulation may continue until steam forms, whereupon the valve 43may be closed, and the pump 36 may be started. The pump may of course beoperated by steam now derived from the generator. Heat is supplied asthe water progresses in its single passage through the generator, untilthe temperature of the water far exceeds 212 F. The time spent by anyportion of water in the generator is only enough to enable it to acquirethe desired degree ofheat once. The smallness of the heating surface isrendered possible by the fact that the water does not circulate aroundand around, but is-heated only once, and as soon as sufficiently heatedis used. The fluid is forced through the system at such a rate that itwill acquire the maximum of heat just as it is about at the lowestpoint.- The constant forced flow of fluid tends towards uniformity ofheat in the Water-pipe system, and hence to prevent excessive heat at aany point. By means of the grid and its distributing headers, the flowof fluid is split up into fine streams, so as to expose it intimately tothe flames, and to heat it quickly, so that it may not remain in thegenerator many minutes, and will not absorb more heat than necessary-toproduce the required delivery of steam.

In the steam delivery main leading from steam drum is arranged a servicesafety valve 82, which,may beset to keep the pressure in thesteam'drum'TS within normal limits: while in a'pipe 83 let into the main46 between the water-reserve drum '37 and the grid system may bearranged an emergency safety valve 84, set at say or 100 pounds higherpressure than the service valve 82 Under ordinary conditions thegenerator will be amply protected by the service valve 8:2; .but if fromany cause there should be a checking of the flow of water through thegrid system. so that. the pressure rises unduly high in the waterreserve drum'37, the emergency safety valve blow ofi". -This notifiesthe engineer steam for a time, until the trouble can be ascertained andremedied. If necessary, the i valve 43 may be opened after the pumpstopped, permitting the water to keep flowing idly through the system,obviating the liability of the overheating of the tubes or pipes at anypoint. This circulation will aflord opportunity for the fire to be drawnor other precautions taken. If desired, a.

back-pressure valve 85 may be arranged in main .39, to prevent liabilityof heating of the pump 36 by hot water or steam.

Variations may be resorted towithin the scope of the invention, andportions of the improvements may be used without others.

Having thus described my invention, I claim: i i

1. A steam boiler system comprising a furnace, a grid of downwardlyextending tubes therein, a pump for forcing water into the upperentrance of said grid, asteam drum above the grid of tubes into whichthe tubes deliver, said'drum having a steam outlet and normally havingcommunication with the grid of tubes only at their endsfurthest from thepump whereby the same water can pass only once through the tubes, andsaid communication means comprising means for reducing the pressure ofthe fluid as it passes from the grid into the drum.

2. A. boiler system comprising a grid .of downwardly extending tubes, apump for pumping Water into the upper entrance end of the tubes, meansfor heating, the tubes to convert the water into steam and a steam drumwithin the furnace above said tubes and normally having communicationonly with the exit ends of the tubes, said drum having a steamoutlet,and said connnunication having thereon means for reducing the pressureof the fluid as it passes from the grid into the drum.

3. A boiler system comprising a furnace,

a grid of tubes zig-zagging hack and forth in the furnace from top tobottom thereof, a pump for pumping water into the upper entrance ends ofthe tubes, and a steam drum within the furnace and normally havingcommunication. only with the exit ends of said grid of tubes, wherebythe same water can pass only oncethrough the tubes. said so f pump forpumping water into the entrance" ends of the tubes, a header into whichsaid tubes discharge, and a steam drum normally having communicationonly with the said header, there being, a pressu e reducing meansbetween the header and the steam drum. v v 5. A boiler system(IOII'IPIlSiH,Q;=L furnace, a header thereon, a grid of tubeszig-zafrging back and forth from the said header to the bottom of thefurnace, means for forcing water into the header and down suid tubes, asteam drum in the top of the furnace normally having communication onlywith the exit ends of the tubes, and u pressure reducing means betweenthe drum and the tubes. t

6. A boiler system comprising a furnace, headers in the upper portion ofthe furnace, grids of tubes in the furnace extending from said headersdownwardly, a pump for pumping water into the headers and tubes, headers in the lower portion of the furnace into which the tubes discharge,a stezun drum into which the lower headers discharge, and pressurereducing means between the lower headers and said stemn drum.

7. A boiler system comprising a l'urnure. a water drum and n steam drumboth inside the furnace and a grid of tubes liming: their entrance endsconnected with the water drum and their discharge ends with the stezundrum and normally forming the only comn'iunieation between said drums,bailic plates in the furnace between. portions of the tubes, u pump forpumping water into the water drum, a steam exit for the steam drunrextending outside the furnace, and pressure reducing means in thesaidconnections between said tubes zind said steam drum.

8. A. boiler system comprising a furnace,

a stezun drum, a water drun'i and water headers inside the upperportions of the furnnce, connections between the waiter drum andheaders, a grid of tubes leading from the headers downwnrdlt through thefurnaee and discharging in the steam drum,

said steam drum having a steam outlet ex tending outside the furnaceand. pressure reducing means governing the said discharge from saidtubes into said steam drum.

HENRY A. moHoLsoN.

